Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754093AbbBRRP7 (ORCPT ); Wed, 18 Feb 2015 12:15:59 -0500 Received: from terminus.zytor.com ([198.137.202.10]:39433 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752553AbbBRRP4 (ORCPT ); Wed, 18 Feb 2015 12:15:56 -0500 Date: Wed, 18 Feb 2015 09:15:06 -0800 From: "tip-bot for Yan, Zheng" Message-ID: Cc: peterz@infradead.org, linux-kernel@vger.kernel.org, zheng.z.yan@intel.com, tglx@linutronix.de, paulus@samba.org, mingo@kernel.org, hpa@zytor.com, kan.liang@intel.com, acme@kernel.org, torvalds@linux-foundation.org Reply-To: zheng.z.yan@intel.com, peterz@infradead.org, linux-kernel@vger.kernel.org, hpa@zytor.com, kan.liang@intel.com, torvalds@linux-foundation.org, acme@kernel.org, mingo@kernel.org, paulus@samba.org, tglx@linutronix.de In-Reply-To: <1415156173-10035-6-git-send-email-kan.liang@intel.com> References: <1415156173-10035-6-git-send-email-kan.liang@intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf: Add pmu specific data for perf task context Git-Commit-ID: 4af57ef28c2c1047fda9e1a5be02aa7a6a69cf9e X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5235 Lines: 180 Commit-ID: 4af57ef28c2c1047fda9e1a5be02aa7a6a69cf9e Gitweb: http://git.kernel.org/tip/4af57ef28c2c1047fda9e1a5be02aa7a6a69cf9e Author: Yan, Zheng AuthorDate: Tue, 4 Nov 2014 21:56:01 -0500 Committer: Ingo Molnar CommitDate: Wed, 18 Feb 2015 17:16:05 +0100 perf: Add pmu specific data for perf task context Introduce a new flag PERF_ATTACH_TASK_DATA for perf event's attach stata. The flag is set by PMU's event_init() callback, it indicates that perf event needs PMU specific data. The PMU specific data are initialized to zeros. Later patches will use PMU specific data to save LBR stack. Signed-off-by: Yan, Zheng Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho de Melo Cc: Linus Torvalds Cc: Paul Mackerras Cc: eranian@google.com Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/1415156173-10035-6-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar --- include/linux/perf_event.h | 6 ++++++ kernel/events/core.c | 40 ++++++++++++++++++++++++++++++++++++---- 2 files changed, 42 insertions(+), 4 deletions(-) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index c7007a5..270cd01 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -271,6 +271,10 @@ struct pmu { */ void (*sched_task) (struct perf_event_context *ctx, bool sched_in); + /* + * PMU specific data size + */ + size_t task_ctx_size; }; @@ -307,6 +311,7 @@ struct swevent_hlist { #define PERF_ATTACH_CONTEXT 0x01 #define PERF_ATTACH_GROUP 0x02 #define PERF_ATTACH_TASK 0x04 +#define PERF_ATTACH_TASK_DATA 0x08 struct perf_cgroup; struct ring_buffer; @@ -511,6 +516,7 @@ struct perf_event_context { u64 generation; int pin_count; int nr_cgroups; /* cgroup evts */ + void *task_ctx_data; /* pmu specific data */ struct rcu_head rcu_head; struct delayed_work orphans_remove; diff --git a/kernel/events/core.c b/kernel/events/core.c index f563ce7..688086b 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -905,6 +905,15 @@ static void get_ctx(struct perf_event_context *ctx) WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); } +static void free_ctx(struct rcu_head *head) +{ + struct perf_event_context *ctx; + + ctx = container_of(head, struct perf_event_context, rcu_head); + kfree(ctx->task_ctx_data); + kfree(ctx); +} + static void put_ctx(struct perf_event_context *ctx) { if (atomic_dec_and_test(&ctx->refcount)) { @@ -912,7 +921,7 @@ static void put_ctx(struct perf_event_context *ctx) put_ctx(ctx->parent_ctx); if (ctx->task) put_task_struct(ctx->task); - kfree_rcu(ctx, rcu_head); + call_rcu(&ctx->rcu_head, free_ctx); } } @@ -3309,12 +3318,15 @@ errout: * Returns a matching context with refcount and pincount. */ static struct perf_event_context * -find_get_context(struct pmu *pmu, struct task_struct *task, int cpu) +find_get_context(struct pmu *pmu, struct task_struct *task, + struct perf_event *event) { struct perf_event_context *ctx, *clone_ctx = NULL; struct perf_cpu_context *cpuctx; + void *task_ctx_data = NULL; unsigned long flags; int ctxn, err; + int cpu = event->cpu; if (!task) { /* Must be root to operate on a CPU event: */ @@ -3342,11 +3354,24 @@ find_get_context(struct pmu *pmu, struct task_struct *task, int cpu) if (ctxn < 0) goto errout; + if (event->attach_state & PERF_ATTACH_TASK_DATA) { + task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL); + if (!task_ctx_data) { + err = -ENOMEM; + goto errout; + } + } + retry: ctx = perf_lock_task_context(task, ctxn, &flags); if (ctx) { clone_ctx = unclone_ctx(ctx); ++ctx->pin_count; + + if (task_ctx_data && !ctx->task_ctx_data) { + ctx->task_ctx_data = task_ctx_data; + task_ctx_data = NULL; + } raw_spin_unlock_irqrestore(&ctx->lock, flags); if (clone_ctx) @@ -3357,6 +3382,11 @@ retry: if (!ctx) goto errout; + if (task_ctx_data) { + ctx->task_ctx_data = task_ctx_data; + task_ctx_data = NULL; + } + err = 0; mutex_lock(&task->perf_event_mutex); /* @@ -3383,9 +3413,11 @@ retry: } } + kfree(task_ctx_data); return ctx; errout: + kfree(task_ctx_data); return ERR_PTR(err); } @@ -7559,7 +7591,7 @@ SYSCALL_DEFINE5(perf_event_open, /* * Get the target context (task or percpu): */ - ctx = find_get_context(pmu, task, event->cpu); + ctx = find_get_context(pmu, task, event); if (IS_ERR(ctx)) { err = PTR_ERR(ctx); goto err_alloc; @@ -7765,7 +7797,7 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, account_event(event); - ctx = find_get_context(event->pmu, task, cpu); + ctx = find_get_context(event->pmu, task, event); if (IS_ERR(ctx)) { err = PTR_ERR(ctx); goto err_free; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/